Interaction of PIN and PGP transport mechanisms in auxin distribution-dependent development
Interaction of PIN and PGP transport mechanisms in auxin distribution-dependent development
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DOI：
10.1242/dev.021071
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发表时间：
2008-10-15
期刊：
影响因子：
4.6
通讯作者：
Friml, Jiri
中科院分区：
文献类型：
--
作者：
Mravec, Jozef;Kubes, Martin;Friml, Jiri
生长素是植物形态发生的信号分子，其活性梯度是由生长素在细胞间的运输产生的。细胞生长素流出是这一过程的限速步骤，并依赖于PIN和磷酸糖蛋白（PGP）生长素转运蛋白。这些蛋白质在生长素运输中的相互作用尚不清楚，它们之间的相互作用对植物发育的意义也不清楚。在这里，我们分析了PIN和PGP依赖的生长素运输在发展中的功能相互作用的重要性。我们通过分析诱导型过表达株系表明，PIN和PGP定义了不同的生长素运输机制：两者都介导生长素流出，但它们发挥着不同的发育作用。这两个系统的组件在胚胎发生，器官发生和向性表达，它们在遗传上相互作用，在协同和拮抗的方式。在这些过程中，生长素的不对称分布需要PIN和PGP依赖的外排系统的协同作用。我们提出了一个模型，其中PGP介导的流出控制生长素通道形成细胞中的生长素水平，从而控制生长素对PIN依赖的矢量生长素运动的可用性。
The signalling molecule auxin controls plant morphogenesis via its activity gradients, which are produced by intercellular auxin transport. Cellular auxin efflux is the rate-limiting step in this process and depends on PIN and phosphoglycoprotein (PGP) auxin transporters. Mutual roles for these proteins in auxin transport are unclear, as is the significance of their interactions for plant development. Here, we have analysed the importance of the functional interaction between PIN- and PGP-dependent auxin transport in development. We show by analysis of inducible overexpression lines that PINs and PGPs define distinct auxin transport mechanisms: both mediate auxin efflux but they play diverse developmental roles. Components of both systems are expressed during embryogenesis, organogenesis and tropisms, and they interact genetically in both synergistic and antagonistic fashions. A concerted action of PIN- and PGP-dependent efflux systems is required for asymmetric auxin distribution during these processes. We propose a model in which PGP-mediated efflux controls auxin levels in auxin channel-forming cells and, thus, auxin availability for PIN- dependent vectorial auxin movement.